Moon told CNN yesterday that he does not agree that tactical nuclear weapons should be reintroduced to South Korea or that Seoul should develop its own nuclear weapons. He warned it could “lead to a nuclear arms race in northeast Asia.” But Lee’s delegation believes that as the North Korea nuclear crisis worsens, a push by the Trump administration or Congress could help persuade Moon’s government to change its position, as it has already done regarding the deployment of the THAAD missile defense system.
First, North Korea is very close to achieving the capability to launch nuclear weapons via both intercontinental ballistic missiles and submarine-launched missiles. That changes the calculus of strategic deterrence. Putting nukes in South Korea would strengthen the ability of the United States and South Korea to retaliate, thereby bolstering that deterrence.